Variation of Fracture Characteristics of Hydroxyl-Terminated Polybutadiene (HTPB)-Based Solid Propellants Under Thermal Aging

Abstract

This study was conducted to investigate the variation of the fracture toughness of hydroxyl-terminated polybutadiene (HTPB) solid propellant. Joint Army Navy NASA Air Force standard tensile tests and essential work of fracture (EWF) tests were carried out using test specimens stored at 20 degrees C and 50 degrees C. In this study, the EWF test results demonstrated that the fracture toughness and crack propagation resistance under plane stress state could be varied due to thermal degradation. The change in key mechanical properties caused by thermal degradation was also examined by the tensile test. The mechanical and fracture properties of the HTPB solid propellant decreased depending on the storage period of the solid propellant. The stability and reliability of the solid propellant were greatly affected by thermal degradation; thus, it is important to monitor the degree of thermal degradation of HTPB solid propellant to ensure proper performance.